Psychological factors play a critical role in lifecycle wealth accumulation. Procrastination and impulsivity undercut wealth accumulation. Bounded rationality and financial illiteracy lead to suboptimal investment decisions. We will study such key psychological factors using a wide range of methods. Our data will include twin studies, household income and wealth surveys, and detailed panel data sets provided by a 401(k) record keeper. We will identify both the psychological factors that influence retirement planning and also identify the prescriptive interventions that can increase the success of lifecycle planning.